In recent years, communication in which a vehicle including a radio communication apparatus performs communication with another vehicle without passing through a base station, that is, vehicle-to-vehicle communication, has been widely studied. Such vehicle-to-vehicle communication is one type of a D2D proximity service. It is noted that the D2D is also referred to as “peer-to-peer (P2P)”.
In the radio communication apparatus configured to perform the vehicle-to-vehicle communication, it is proposed a technology for controlling a directivity of a radio signal to be transmitted and received (see Patent Document 1). Specifically, in the radio communication apparatus described in the Patent Document 1, if it is determined that the vehicle including the radio communication apparatus enters a traffic intersection, the directivity is changed from a traveling direction to a right-and-left direction to make the vehicle-to-vehicle communication smooth with another vehicle running in the right-and-left direction relative to the traveling direction of the vehicle.